For the child who is apathetic and mentally weak, It would
be necessary, however, to begin with exercises in which the stimuli
are more strongly contrasting and would be reached in this exercise
after many others had been taken.
For normal children this is the first object which may be
presented, and from among all the sense material this is the object
preferred by little children of two and a half to three and a half
years of age.
For defectives, when they reached this object, it was necessary
to attract their attention continually and firmly, inviting observation
and comparison; the child, having gathered all the cylinders once
into their places, stopped, and the game was finished. When the
defective made mistakes, he had to be corrected, or urged to correct
himself, and even when he managed to recognize a mistake it
generally left him indifferent.
It is different with the normal child who of his own free will
takes the liveliest interest in the game, corrects himself, while the
correction itself leads to an intensification of his attention on the
differences in dimensions and in making comparisons among them.
When the normal child is absorbed in his work he refuses
interference from those who want to step in and help him; he
wants to be left alone with his problem. The result is a voluntary
activity which has a much higher value than simply clearing up
the differences between things. Used in this way the material
reveals itself as a key which puts the child in communication with
himself and opens his mind to expression and activity.
Concentration on a voluntary exercise repeated a great many
times is the index to the superiority of the normal child.
Another difference is found in the distinction which the normal
child is capable of making between essential things and secondary
things which often serve to throw the others into relief.
It has been said that there enters into the education of
the senses the isolation of the sense which is to be exercised.
Thus, when establishing tactile differences, it is a good plan to
isolate the child from visual impressions either by making the